offertory [Lat., = offering], in the Roman Catholic Mass and in derived liturgical forms, the preparation of bread and wine on the altar and their formal offering to God. It takes place after the gospel and the creed and before the preface. A short psalm verse from Scriptures is appointed to be said or sung at the beginning; it varies from day to day. This is called the offertory verse. From ancient times it has been customary to collect the alms of the worshipers about the time of the offertory, hence the term has been transferred to the collection taken up in services in Protestant churches and to the music played or sung during the collection. The choice of this selection is usually left to the musicians of the church, and in many Protestant churches the offertory is the choir's principal musical selection in the service.